Lesion preparation

9.7.1.3.1

Perforation

Causes:

• Wire entered small distal branch.

Prevention:

• Ensure optimal distal guidewire position (wire should not be in a small branch to minimize the risk of distal coronary perforation; this is, especially important for branches located close to the occlusion, as the balloon may enter that branch and perforate it while dilating the lesion).

Treatment:

• Treatment of perforation is discussed in Chapter 26 : Perforation.

9.7.2.3.1

Distal embolization ( Section 25.2.3 )

Causes:

• Air sucked into the guide catheter during balloon withdrawal. This is more likely when withdrawing large balloons.

• Thrombus or plaque entry into the guide catheter while withdrawing a balloon (may be more likely with bulky large diameter balloons, or plaque modification balloons, such as the Angiosculpt, Chocolate, and cutting balloon, Section 30.9.3 ).

Prevention:

• Guide aspiration followed by flushing, as described above.

Treatment:

• Air embolization is treated with administration of 100% oxygen, possibly aspiration, and administration of intracoronary epinephrine in case of cardiac arrest. Air embolization usually resolves with supportive measures without needing additional intervention. Air embolization is described in detail in Section 25.2.3.3 .

• Embolization of plaque or thrombus is usually treated with thrombectomy, as described in Chapter 20 : Acute coronary syndromes—thrombus.

9.7.3.2.1

Balloon diameter

For achieving lesion expansion : for most lesions the balloon diameter is chosen to match the distal reference vessel diameter (1:1 ratio). The goal is to determine whether the balloon fully expands and therefore no additional lesion modification is needed before stenting. This is particularly important for calcified and in-stent restenotic lesions.

For crossing : for very tight lesions that are hard to cross, small balloons (≤1.5 mm, Section 30.9.2 ) are initially used to modify the lesion entry point and allow subsequent delivery of larger balloons to further modify the lesion before stent placement.

9.7.3.2.2

Balloon length

Balloon length should be shorter than the estimated lesion length (to avoid injury of coronary segments proximal or distal to the target lesion that will require implantation of longer length stents).

9.7.3.2.3

Balloon compliance

Noncompliant balloons are preferred, because they can also be used for postdilation of the target lesion after stenting. However, they are less deliverable than compliant balloons.

9.7.3.2.4

Balloon delivery system

There are two balloon delivery systems: monorail and over-the-wire. Monorail balloons should be used in the vast majority of cases, as they are simpler to use, do not require use of long guidewires, and are easier to deliver because they have a stiffer shaft.

9.7.3.2.5

Plaque modification balloons

Some balloons have nitinol wires (such as the Angiosculpt and the Chocolate) or cutting blades (cutting balloon) aiming to modify the lesion and facilitate expansion ( Section 30.9.3 ). Plaque modification balloons are harder to deliver (due to larger profile and lesser flexibility). The cutting balloon also requires slow inflation and deflation. Plaque modification balloons can, in some cases, facilitate expansion of “balloon undilatable lesions” ( Section 23.2 ). The SIS OPN balloon ( Section 30.9.7 ) can be very useful for dilating resistant lesions, but is not currently available in the United States.

9.7.4.4.1

Inability to visualize balloon when inflated

Causes:

• Inadvertent filling of the balloon with saline instead of contrast solution.

• Poor balloon preparation with significant amount of air remaining in the balloon.

Prevention:

• Ensure that diluted contrast (and not pure saline) is used to prepare and inflate the balloon. The syringe containing the contrast/saline solution should be appropriately labeled.

• Ensure that air is removed during balloon preparation.

Treatment:

• If balloon cannot be visualized once inflated, it should be prepared again using a contrast solution and optimal preparation technique.